The present assignee holds a number of patents describing removable cartridge disk drives and cartridges therefore. By way of example, these patents include U.S. Pat. No. 4,503,474 issued Mar. 5, 1985; U.S. Pat. No. 4,504,879 issued Mar. 12, 1985; U.S. Pat. No. 4,717,981 issued Jan. 5, 1988; U.S. Pat. No. 4,683,506 issued Jul. 28, 1987; U.S. Pat. No. 4,722,012 issued Jan. 26, 1988; U.S. Pat. No. 4,870,518 issued Sep. 26, 1989; U.S. Pat. No. 4,965,685 issued Oct. 23, 1990; and U.S. Pat. No. 4,864,452 issued Sep. 5, 1989. All of these references are incorporated herein by reference. These patents are directed to a removable cartridge disk drive which can receive a cartridge containing a hard disk upon which can be stored substantial amounts of data comparable, in some cases, to that stored on fixed disk drives.
In reviewing these patents, it is evident that design challenges reside in accurately receiving the cartridge into the disk drive cartridge receiver and settling the hub of the cartridge repeatedly and accurately onto the spindle shaft of a spindle motor. The spindle motor causes the disk contained in the cartridge to rotate at the appropriate operating speed. Design challenges also reside in the ability of the head and head arm assembly, located in the disk drive, to be positioned through a door in the cartridge in order to be loaded onto the disk contained in the cartridge for the read/write operations. Further, the design feature of reliably ejecting the cartridge from the disk drive once the read/write operations have been concluded is addressed.
A removable cartridge disk drive is highly useful for a number of reasons. The first reason is that a substantial amount of data can be stored on the cartridge, the cartridge can be removed, and, if desired, conveniently shipped to another location. With the requirement to transport ever increasing amounts of data, as for example found in graphics files, the removable cartridge can store a substantial amount of data which would otherwise require a multitude of floppy disks. The data can thus be conveniently sent to, for a example, a publisher for publishing the graphics.
A second reason for such designs is that removable cartridge disk drives have an infinite capacity. Once a cartridge is filled with data, the cartridge can be replaced with a blank cartridge. Unlike with fixed drives, there is no need to trade up to a higher capacity disk drive or to purge lesser used documents from the hard disk drive.
A third reason is that if confidential or secret information is contained on the disk, the disk can be removed from the disk drive and secured in a safe location so that the data cannot be accessed by unauthorized individuals.
The trend in the computer market, and in particular the personal computer market, is to develop smaller, higher capacity and less expensive hardware. Thus, what used to be acceptable as far as performance and capacity in a desk top computer is now required for a notebook computer but at a substantially reduced size. Accordingly, there is a need to provide computer hardware, and for example, a removable cartridge disk drive and removable cartridge which is smaller, easier to manufacturer, as for example, having fewer parts, and with higher data capacity.